Full-Genome Sequence of a Novel Varicella-Zoster Virus Clade Isolated in Mexico

Differential Diagnosis, Prevention, and Treatment of mpox (Monkeypox): A Review for Dermatologists

The current 2022 mpox (monkeypox) outbreak has been officially recognized as a public health emergency. The mpox clinical symptoms include high fever, fatigue, chills, headache, swollen lymph nodes, muscle aches, and a disseminated painful rash. However, recent cases of mpox have shown a shift in clinical symptoms, with anogenital skin lesions emerging as the predominant feature. Due to the predominant skin manifestations of mpox, dermatologists could be crucial in detecting new mpox cases and educating frontline healthcare professionals about mpox. The mpox virus is continuously evolving and has several variants. Genome sequencing has revealed that the Clade IIb variant is responsible for the 2022 mpox outbreak. Mpox spread may occur through animal-to-human and human-to-human transmission; however, unlike coronavirus disease 2019 (COVID-19), long-range airborne transmission has not been reported. Healthcare professionals are at higher risk of becoming infected since they are usually in close contact with both the patients and potentially contaminated fomites (e.g., examination table, gowns, gloves). Both public and healthcare professionals should take preventive and avoidance measures to limit the spread. Mpox is usually self-limiting and may require only symptomatic treatment; however, it may cause severe complications in special populations such as immunocompromised individuals. For severe infection, clinicians may consider antiviral drugs (off-label), tecovirimat and brincidofovir, originally approved for smallpox treatment. Two smallpox vaccines, ACAM2000^® and JYNNEOS^TM, can be used as pre-exposure prophylaxis against mpox. JYNNEOS^TM, which carries approval for mpox use, has less adverse effect potential than ACAM2000^®, and may also be used as post-exposure prophylaxis, preferably within 4 days of exposure.

Human herpesvirus diversity is altered in HLA class I binding peptides

Herpesviruses are ubiquitous, genetically diverse DNA viruses, with long-term presence in humans associated with infrequent but significant pathology. Human leukocyte antigen (HLA) class I presents intracellularly derived peptide fragments from infected tissue cells to CD8+ T and natural killer cells, thereby directing antiviral immunity. Allotypes of highly polymorphic HLA class I are distinguished by their peptide binding repertoires. Because this HLA class I variation is a major determinant of herpesvirus disease, we examined if sequence diversity of virus proteins reflects evasion of HLA presentation. Using population genomic data from Epstein–Barr virus (EBV), human cytomegalovirus (HCMV), and Varicella–Zoster virus, we tested whether diversity differed between the regions of herpesvirus proteins that can be recognized, or not, by HLA class I. Herpesviruses exhibit lytic and latent infection stages, with the latter better enabling immune evasion. Whereas HLA binding peptides of lytic proteins are conserved, we found that EBV and HCMV proteins expressed during latency have increased peptide sequence diversity. Similarly, latent, but not lytic, herpesvirus proteins have greater population structure in HLA binding than nonbinding peptides. Finally, we found patterns consistent with EBV adaption to the local HLA environment, with less efficient recognition of EBV isolates by high-frequency HLA class I allotypes. Here, the frequency of CD8+ T cell epitopes inversely correlated with the frequency of HLA class I recognition. Previous analyses have shown that pathogen-mediated natural selection maintains exceptional polymorphism in HLA residues that determine peptide recognition. Here, we show that HLA class I peptide recognition impacts diversity of globally widespread pathogens.

Varicella-Zoster Virus-Genetics, Molecular Evolution and Recombination

This chapter first details the structure, organization and coding content of the VZV genome to provide a foundation on which the molecular evolution of the virus can be projected. We subsequently describe the evolution of molecular profiling approaches from restriction fragment length polymorphisms to single nucleotide polymorphism profiling to modern day high-throughput sequencing approaches. We describe how the application of these methodologies led to our current model of VZV phylogeograpy including the number and structure of geographic clades and the role of recombination in reshaping these.

Epidemiological surveillance of chikungunya fever in Mexico since its introduction in 2014-2016 and identification of circulating genotypes

In 2014, the chikungunya virus (CHIKV) was detected for the first time in Mexico, the identified strain was the one corresponding to the Asian genotype which was phylogenetically grouped with the strains that circulated in the British Virgin Islands outbreak and was later classified with lineages of Caribbean strains. In three years, 13,569 cases of chikungunya were registered in Mexico. Although the transmission and spread of the virus are now considered a moderate risk, the danger that the virus reemerges is not ruled out due to the infestation of Aedes mosquitoes. In this study, we reviewed the chikungunya fever (CHIKF) cases reported between 2014 and 2016 to reanalyze the data. Seventeen cases were selected from different states where the circulation of the virus had been reported. Statistical data were analyzed and a retrospective analysis was carried out. Nucleic acid sequences were determined of these 17 samples. 2015 was the year with the highest number of cases (92.8%) and they were detected in 28 states of the country. There is a predominance of females, and the most affected age group was between 25 and 44 years. In 2016, CHIKV genotypes were not known, in this study the presence of the Asian genotype of Caribbean lineage was confirmed. The presence of the West African and ECSA genotypes was phylogenetically ruled out. The sequences obtained were deposited in GeneBank.

Utility of high-throughput DNA sequencing in the study of the human papillomaviruses

The Papillomaviridae family is probably the most diverse group of viruses that affect vertebrates. The study of the relationship between infection by certain types of human papillomavirus (HPV) and the development of neoplastic epithelial lesions is of particular interest because of the high prevalence of HPV-related carcinomas in populations of developing countries. To understand the mechanisms of infection and their association with different clinical manifestations, molecular tools play an important role in the description of new types of HPV, the characterization of effector properties of the viral factors, the specific diagnosis and monitoring of HPV types, and the alteration patterns at genetic level in the host. Technological advances in the field of DNA sequencing have led to the development of different next-generation sequencing systems, allowing obtaining a large amount of data and broadening the applications to study viral diseases. In this review, we summarize the main approaches and their perspectives where the use of massively parallel sequencing has been proved as a useful tool in the research of the HPV infection.